I have recently used Ice Cream Sandwich and I really like the Holo theme. I would like to be able to use this theme for lower Android API versions (Gingerbread, Froyo, Eclair, etc). Is there a way to port this theme to older versions of Android, or any other way that I could use it?

a lot of apps on my Gingerbread devices use the holo theme, so I'd answer this with a clear "Yes". But if your question is about how to integrate it with an app you develop, I'd suggest you flag your question to be migrated to stackoverflow (as development questions are off-topic here).
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IzzyAug 3 '12 at 12:50